Plastic spout

ABSTRACT

A plastic spout  150,170  which is adapted to be sealed between two foil walls of a pouch. The spout has a spout body, which forms a passage  153  for delivering a medium from the pouch and/or feeding a medium to the pouch. In a bottom part thereof, the spout, on opposite sides, forms a sealing zone for a sealed connection to an adjoining foil wall. The sealing zones of the spout body are formed by sealing walls  158,159  which project downward from the spout body, each having a curvature over their entire length, such that each sealing wall is outwardly convex over its entire length with respect to an imaginary plane passing through the outermost ends, which adjoin one another, of the sealing walls. The sealing walls can preferably move flexibly transversely with respect to their plane and, on their inner side, are unsupported or are supported by one or more flexible supporting parts of the spout body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the national stage filing under 35 U.S.C. §371 ofPCT/NL02/00646, filed Oct. 10, 2002, which claims priority to NL1019161, filed Oct. 11, 2001 which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a plastic spout which is intended to besealed between two foil walls of a pouch, comprising a spout body whichforms a passage for delivering a medium from the pouch and/or feeding amedium to the pouch, which spout body, on opposite sides, forms asealing zone for sealed connection to the adjoining foil wall.

The present invention also relates to a method for sealing a plasticspout between two foil layers of a pouch.

BACKGROUND OF THE INVENTION

WO 00/66448, in particular FIGS. 9 a–d, in the name of the presentapplicant has disclosed a plastic spout, which is adapted to be sealedbetween two foil walls of a pouch. The known spout has a spout body witha central tubular part which forms a passage for delivering a mediumfrom the pouch and/or feeding a medium to the pouch, the medium being,for example, a liquid, powder or gas.

The known spout body, on opposite sides thereof, forms a sealing zonefor the adjoining foil wall. These sealing zones are formed by ribs,which project outwards from the central tubular part, lie at an axialdistance from one another and adjoin bridge parts, which liediametrically with respect to the tubular part. The ends of the bridgeparts end in thin lips. As seen in the plane running transversely withrespect to the tubular part of the spout body, the ribs, together withthe adjoining bridge parts and the lips, form a boat-shaped contour ontheir outer circumference.

During the sealing, the known spout body is introduced between the foilwalls of a pouch and a fused join is brought about between the sealingzones of the spout, which are formed by the outermost surfaces of theribs, the bridge pieces and the lips, on the one hand, and the adjoiningparts of the foil walls of the pouch, on the other hand.

The known spout body does not always prove satisfactory, in particularwith regard to the sealed connection between the foil walls and thespout body. For example, one drawback is that producing the sealedconnection requires undesirably large amounts of heat and time, with theresult that the production rate is undesirably low. In practice, thissealing time is shortened by greatly increasing the pressure with whichthe foil walls are pressed onto the sealing zones, but this leads to apoor-quality sealed connection.

Another drawback of this known spout is that with certain types of foil,for example foil with a layer of aluminum, the ribs in the sealing zonesmay cause damage to the foil.

JP2001-240083 has disclosed a spout the spout being provided on theunderside with downward projecting thin sealing walls, which betweenthem delimit a substantially oval space. When this known spout is beingsealed between the foil walls of a pouch, the spout is first of allplaced onto a support member which fits into the oval space. During thesealing, heated sealing jaws are placed onto the outer side of the foilwalls, so that the sealing walls and adjoining foil walls, which areclamped between the support member and the sealing jaws, fuse and awelded joint is formed. The support member holds the sealing walls inthe intended shape in this arrangement. The sealing walls are designedto be thin, making it possible to produce the sealed connection morequickly.

One drawback of the spout described in JP2001-240083 is that the supportmember requires the pouch to be open on the underside, so that thesupport member can project outwards. Furthermore, positioning the spouton the support member and removing the pouch from the support memberafter sealing has taken place takes up time, which once again slows theproduction process.

OBJECTS OF THE INVENTION

It is an object of the present invention, according to a first aspectthereof, to provide a spout which can be sealed in place without usingthe support member. It is a further object to provide a method to seal aplastic spout between two foil walls of a pouch.

SUMMARY OF THE INVENTION

For this purpose the first aspect of the invention provides a spout,which is characterised in that the sealing walls each have a curvatureover their entire length, such that each sealing wall is outwardlyconvex over its entire length with respect to an imaginary plane passingthrough the outermost ends, which adjoin one another, of the sealingwalls.

This design of the sealing walls means that the sealing walls are stableif, during the sealing operation, external pressure is applied to thesealing walls by means of pressure-exerting means, such as heatedsealing jaws. Even with a low thickness of the sealing walls (less than2 millimeters), this stability is such that there is no need to use asupport member during the sealing operation, with the result that thesupport member is preferably omitted.

When the spout is being sealed in place, only a small amount of heat isrequired to melt the sealing walls on the side of the foil walls whichhave been pressed onto them. This is because the heat which is suppliedduring sealing cannot be dissipated to parts of the spout which liefurther away from the surface which is to be melted.

The heat required to form a seal can be provided using all known sealingmethods, for example using heated sealing jaws and/or with the aid ofultrasound.

Further advantages of the spout with sealing walls according to thefirst aspect of the invention relate to the production of the spout in asuitable injection mould. This mould can be of relatively simple design,and furthermore the sealing walls require little plastic material. It isalso possible for the cooling time for the sealing walls in the mould tobe short, which is advantageous with regard to the production rate andcost price. Moreover, on account of the sealing walls, the mould can beprovided with simple and efficient cooling means. In particular, themould part which defines the inner side of the sealing walls and iscomposed of one or more components can be designed with a relativelylarge volume of material, so that there is space for efficient coolingmeans therein.

It is preferable for the sealing walls to be designed to be thin. Thewall thickness of the sealing walls is in practice preferably at most 2millimeters. The invention provides the possibility for the sealingwalls to be designed with a thickness which as a minimum corresponds tothe thickness of the foil walls.

It is preferable for the spout to be designed in such a manner that thesealing walls can move flexibly transversely with respect to their planeand on their inner side to be unsupported or supported by one or moreflexible supporting parts of the spout body. Then, after the spout hasbeen fitted in the pouch, these sealing walls have a shock-absorbingcapacity and can yield elastically with foil walls of the pouch. Thisreduces the risk of damage to and possible leaks from the pouch at thelocation of the transition from the foil wall to a sealing wall.Furthermore, the flexibility of the sealing walls is advantageous forthe production of the sealed connection, for example because broaderdimensional tolerances of the spout body are acceptable without havingan adverse effect on correct operation of the sealing device.

In a preferred embodiment, it is provided that the outer sides of thesealing walls, against which the foil walls come to bear, are of smoothdesign, i.e. without ribs or the like. This design is advantageous, forexample, if the foil wall includes one or more layers of metal foil, inparticular aluminum foil.

It is preferable for the spout body to comprise a transverse wall whichextends transversely between the sealing walls, the passage extendingthrough the transverse wall. The transverse wall is preferably situatedat or close to the upper edge of the sealing walls. For example, anoutwardly projecting tubular part of the spout body, which forms thepassage, adjoins the transverse wall.

The first aspect of the invention also relates to the sealing of aplastic spout between foil walls, in particular of a pouch. In thisaspect, use is made of pressure-exerting means which press the foilwalls onto the sealing walls of the pouch without a support memberinternally supporting the sealing walls. In an advantageous embodiment,during the sealing of the spout use is made of pressure-exerting meanswhich yield elastically to press the foil walls onto the sealing wallsof the spout. By way of example, use is made of pressure-exerting jawswith an elastic layer, for example made from heat-resistant foammaterial.

In an advantageous embodiment, the spout or just the sealing wallsis/are preheated before the spout is sealed into the pouch.

A second aspect of the invention relates to a spout in which the sealingwalls are connected via flexible connecting bodies to a tubular partwhich fits between the sealing walls.

A third aspect of the invention provides a spout which is characterisedin that the transverse wall is provided with one or more corrugationstransversely with respect to the plane of the transverse wall, whichimpart flexibility to the transverse wall, in such a manner that thetransverse wall allows the flexible movement of the sealing walls. Theresult of this measure is that the transverse wall does not cancel outthe intended flexibility of the sealing walls, so that theshock-absorbing capacity and the sealing properties are positivelyinfluenced compared to a transverse wall which is of rigid design.

The present invention also relates to a pouch provided with a spoutaccording to the invention.

Further advantageous embodiments of the spout according to the variousaspects of the invention are described in the claims and the followingdescription with reference to the drawing. The drawing is on asignificantly enlarged scale compared to reality.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows a side view of a first exemplary embodiment of theplastic spout according to the first aspect of the invention,

FIG. 1 b shows a front view of the spout shown in FIG. 1 a,

FIG. 1 c shows a view from below of the spout shown in FIG. 1 a,

FIG. 1 d shows a perspective view of the spout shown in FIG. 1 a fromabove,

FIG. 1 e shows a perspective view of the spout shown in FIG. 1 a frombelow,

FIG. 2 a shows a side view of a second exemplary embodiment of theplastic spout according to the first aspect of the invention,

FIG. 2 b shows a front view of the spout shown in FIG. 2 a,

FIG. 2 c shows a view from below of the spout shown in FIG. 2 a,

FIG. 2 d shows a perspective view of the spout shown in FIG. 2 a fromabove,

FIG. 2 e shows a perspective view of the spout shown in FIG. 2 a frombelow,

FIG. 3 a shows a side view of an exemplary embodiment of the plasticspout according to the second aspect of the invention,

FIG. 3 b shows a front view of the spout shown in FIG. 3 a,

FIG. 3 c shows a view from below of the spout shown in FIG. 3 a,

FIG. 3 d shows a perspective view of the spout shown in FIG. 3 a fromabove,

FIG. 3 e shows a perspective view of the spout shown in FIG. 3 a frombelow,

FIG. 4 a shows a side view of an exemplary embodiment of the plasticspout according to the third aspect of the invention,

FIG. 4 b shows a front view of the spout shown in FIG. 4 a,

FIG. 4 c shows a view from below of the spout shown in FIG. 4 a,

FIG. 4 d shows a perspective view of the spout shown in FIG. 4 a fromabove,

FIG. 4 e shows a perspective view of the spout shown in FIG. 4 a frombelow.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1 a–e show a spout 150 which is produced by injection-mouldingfrom a suitable plastic material and which is intended to be sealedbetween two foil walls of a pouch.

The spout 150 has a single-part spout body with, on the top side, anoutwardly projecting tubular part 152 which forms a passage 153 fordelivering a medium from the pouch and/or feeding a medium to the pouch.

The tubular part 152 is provided with a screw thread 154 for a screw cap(not shown), which can be used to close off the spout 150.

The outwardly projecting tubular part 152 is furthermore provided with alocking flange 155 for the screw cap and, beneath this, twocircumferential flanges 156 which are used for handling means for thespout 150 and the pouch to engage on after the spout 150 has been sealedin the pouch.

On the underside, the spout 150 is provided with two sealing walls 158,159 which project freely downwards, adjoin one another at theirdiametrically opposite ends and have an oval contour both on the innerside and on the outer side. The sealing walls 158, 159 adjoin theremainder of the spout body 150 only at their upper edge. Therefore, thesealing walls 158, 159 between them delimit an oval space.

In particular, the sealing walls 158, 159 have a curvature over theirentire length, in such a manner that each sealing wall 158, 159 isexternally convex with respect to the imaginary line passing through theoutermost ends, which adjoin one another, of the sealing walls. This ismore stable than the design which is known from the prior art in whichthe sealing walls have straight wall parts, and certainly more stablethan the design according to the prior art in which the sealing wallshave parts with an inwardly directed convexity. The latter variantsprovide too little resistance to the sealing walls being undesirablyfolded inwards, for example while the sealed connection is beingproduced.

The sealing walls 158, 159 are designed to be smooth on the outer side.The sealed connection to the foil walls can then be produced overvirtually the entire surface of the thin sealing walls 158, 159. In thiscontext, the thin design of the sealing walls 158, 159 makes asignificant contribution to the short sealing time, since little heathas to be supplied in order to produce the fused connection.

The sealing walls 158, 159 have no internal support and are flexiblymovable and can easily be moved transversely with respect to the planeof the sealing walls 158, 159.

The flexibility of the sealing walls 158, 159 provides the pouch with ashock-absorbing capacity, as can be seen from a test which involvesdropping a filled pouch. Furthermore, the flexibility of the sealingwalls 158, 159 avoids overloading the foil walls of the pouch in thevicinity of the bottom edge of the sealing walls 158, 159.

When the sealed connection is being produced, it is preferable to usejaws which completely surround the sealing walls, so that a sufficientpressure can then be obtained between the foil walls and the sealingwalls.

In a variant, to produce the sealed connection sealing jaws which areprovided with ribs or another profile, for example a waffle profile or ablock profile, are used instead of sealing jaws with smooth jawsurfaces, so that the initial pressure is exerted at the location of theelevated parts of the profile.

In the spout 170 shown in FIGS. 2 a–e, the sealing walls 171, 172 aredesigned with an even greater curvature than in the embodiment shown inFIG. 1.

At the location where the sealing walls 171, 172 meet, outwardlyprojecting thin lips 173, 174 are formed, these lips forming thetransition to the parts of the foil walls of the pouch which are sealedtogether.

The inner side of the sealing walls may be of smooth design, as shown inthe drawings, but it would also be possible to provide one or moreformation, for example a thickened edge or a groove, in order to secureanother component in the space between the sealing walls. By way ofexample, in this way it is possible for a flexible insert to be clippedinto place, reducing the size of the effective area of the passage.

The spout 90 according to the second aspect of the invention will now beexplained in more detail with reference to FIGS. 3 a–e.

The spout 90 has a single-part spout body with, at the top side, anoutwardly projecting tubular part 92 which forms a passage 93 fordelivering a medium from the pouch and/or feeding a medium to the pouch.

The tubular part 92 is provided with a screw thread 94 for a screw cap(not shown), which is used to close off the spout 90.

The outwardly projecting tubular part 92 is furthermore provided withtwo circumferential flanges 95, which are used for handling means forthe spout 90 and the pouch to engage on after the spout 90 has beensealed into the pouch.

On the underside, the spout 90 is provided with two sealing walls 98, 99which project freely downwards and have an eye-shaped contour both onthe inner side and on the outer side. Since the sealing walls 98, 99have straight parts in the vicinity of their ends, these sealing wallsdo not comply with the first aspect of the invention.

On the underside, the spout body 90 comprises a tubular part 100 whichextends in line with the tubular part 92 and the diameter of which issmaller than the corresponding dimensions of the space delimited by thesealing walls 98, 99.

The tubular part 100 is connected to the inner side of the sealing walls98, 99 via two diametrically opposite flexible connecting bodies 101,102. In this case, the connecting bodies 101, 102 are provided with acurvature and are therefore flexible, so that the connecting bodies 101allow the flexible movement of the sealing walls 98, 99.

The spout 110 according to the third aspect of the invention will now beexplained in more detail with reference to FIGS. 4 a–e.

The spout 110 has a single-part spout body with, at the top side, anoutwardly projecting tubular part 112 which forms a passage 113 fordelivering a medium from the pouch and/or feeding a medium to the pouch.

The tubular part 112 is provided with a screw thread 114 for a screw cap(not shown), which is used to close off the spout 110.

The outwardly projecting tubular part 112 is furthermore provided withtwo circumferential flanges 115, which are used for handling means forthe spout 110 and the pouch to engage on after the spout 110 has beensealed into the pouch.

On the underside, the spout 110 is provided with sealing walls 118, 119which project freely downwards and have an eye-shaped contour both onthe inner side and on the outer side.

On the underside, the spout body 110 comprises a tubular part 120 whichextends in line with the tubular part 112 and the diameter of which issmaller than the internal dimensions of the space delimited by thesealing walls 118, 119.

A transverse wall 122, which is provided with corrugations, extendsbetween the sealing walls 118, 119, so that the transverse wall isflexible and allows the flexible movement of the sealing walls 118, 119.

The transverse wall 122 also forms a flexible connection between thetubular parts 112, 120, which lie in line with one another, on the onehand, and the sealing walls 118, 119, on the other hand.

The design of the spout shown in FIG. 4 is highly advantageous withregard to the shock-absorbing capacity of the pouch. The pressure whichis formed in the medium in the pouch in a test which involves droppingthe pouch, in particular where the medium is a liquid, will now lead toelastic deformation of the transverse wall 122 (and also of the sealingwalls), so that there is no pressure surge leading to (a seam of) thepouch giving way.

It will be clear that the spout body may have all kinds of designs, forexample may be designed in combination with a stopper for closing offthe passage, a male element if the spout is used as a connector, etc.

1. A plastic spout which is adapted to be sealed between two foil wallsof a pouch, comprising a spout body which forms a passage for deliveringa medium from the pouch and feeding a medium to the pouch, which spoutbody, in a bottom part thereof, on opposite sides forms a sealing zonefor a sealed connection to an adjoining foil wall, the sealing zones ofthe spout body being formed by sealing walls which project downwardsfrom the spout body, each sealing wall having outermost ends and alength, the sealing wall ends adjoining one another and between themdelimiting an oval space, wherein the sealing walls each have acurvature over their entire length, such that each sealing wall isoutwardly convex over its entire length with respect to an imaginaryplane passing through the outermost ends, which adjoin one another, ofthe sealing walls, wherein the spout body comprises a transverse wall,which extends transversely with respect to the sealing walls, and inwhich the passage extends through the transverse wall, and in which thetransverse wall is provided with one or more corrugations transverselywith respect to the plane of the transverse wall, which impartflexibility to the transverse wall, in such a manner that the transversewall allows the flexible movement of the sealing walls.
 2. A plasticspout which is adapted to be sealed between two foil walls of a pouch,comprising a spout body which forms a passage for delivering a mediumfrom the pouch and feeding a medium to the pouch, which spout body, in abottom part thereof, on opposite sides forms a sealing zone for a sealedconnection to an adjoining foil wall, the sealing zones of the spoutbody being formed by sealing walls which project downwards from thespout body, each sealing wall having outermost ends and a length, thesealing wall ends adjoining one another and between them delimiting anoval space, wherein the sealing walls each have a curvature over theirentire length, such that each sealing wall is outwardly convex over itsentire length with respect to an imaginary plane passing through theoutermost ends, which adjoin one another, of the sealing walls, whereinthe spout body comprises a V-shaped or U-shaped transverse wall, whichconnects the upper edges of the sealing walls to one another and whichextends transversely with respect to the sealing walls, and in which thepassage extends through the transverse wall, and in which the transversewall is provided with one or more corrugations transversely with respectto the plane of the transverse wall, which impart flexibility to thetransverse wall, in such a manner that the transverse wall allows theflexible movement of the sealing walls.
 3. A plastic spout which isadapted to be sealed between two foil walls of a pouch, comprising aspout body which forms a passage for delivering a medium from the pouchor feeding a medium to the pouch, which spout body comprises a tubularpart which delimits at least a part of the passage of the spout, andwhich spout body, in a bottom part thereof, on opposite sides, forms asealing zone for a sealed connection to an adjoining foil wall, thesealing zones of the spout body being formed by sealing walls whichproject downwards from the spout body and between them delimit an ovalspace, wherein the tubular part extends as far as between the sealingwalls and, via one or more flexible connecting bodies, adjoins the innerside of the sealing walls wherein each connecting body is provided withone or more corrugations for creating the flexibility.
 4. A plasticspout adapted to be sealed between two foil walls of a pouch, comprisinga spout body which forms a passage for delivering a medium from thepouch or feeding a medium to the pouch, which spout body, in a bottompart thereof, on opposite sides forms a sealing zone for a sealedconnection to an adjoining foil wall, the sealing zones of the spoutbody being formed by sealing walls which project downwards from thespout body, the spout body comprising a transverse wall having a planewhich extends transversely with respect to the sealing walls, and thepassage extending through the transverse wall, wherein the transversewall is provided with one or more corrugations transversely with respectto the plane of the transverse wall, which impart flexibility to thetransverse wall, in such a manner that the transverse wall allows theflexible movement of the sealing walls.
 5. A spout according to claim 4,in which a V-shaped transverse wall connects the upper edges of thesealing walls to one another.
 6. A spout according to claim 4, in whicha U-shaped transverse wall connects the upper edges of the sealing wallsto one another.
 7. A method for sealing a plastic spout between two foilwalls of a pouch, which spout comprises a spout body which forms apassage for delivering a medium from the pouch or feeding a medium tothe pouch, which spout body, in a bottom part thereof, on opposite sidesforms a sealing zone for sealing to an adjoining foil wall, the sealingzones of the spout body being formed by thin, flexible sealing wallswhich project downwards from the spout body and between them delimit asubstantially oval space, which sealing method comprises the step ofpressing the foil walls onto the sealing walls using pressure-exertingmeans, wherein the sealing walls of the spout body each have a curvatureover their entire length, such that each sealing wall is outwardlyconvex over its entire length with respect to an imaginary plane passingthrough the outermost ends, which adjoin one another, of the sealingwalls, the pressure-exerting means press the foil walls onto the sealingwalls of the pouch without a support member internally supporting thesealing walls and further, in which the spout body comprises atransverse wall, which extends transversely with respect to the sealingwalls, and in which the passage extends through the transverse wall andwherein the transverse wall is provided with one or more corrugationstransversely with respect to the plane of the transverse wall, whichimpart flexibility to the transverse wall, in such a manner that thetransverse wall allows the flexible movement of the sealing walls. 8.Method according to claim 7, in which a V-shaped transverse wallconnects the upper edges of the sealing walls to one another.
 9. Methodaccording to claim 7, in which a U-shaped transverse wall connects theupper edges of the sealing walls to one another.